Lighting-fixture.



W. LUMLEY.

LIGHTING FIXTURE.

APPLICATION FILED MAY 5, 1913.

1,230,??? I PzitentedJune 19,1917.

WTNESSES 1N PEN TOR v 1 WLifi/flLUMLEX silience of the material inmaintainin engagement between the arm and the WILFRIID LUMLEY, OFCONIIEAUT, OHIO, ASSIGNOB'TO' GENERAL ELECTRIG- COMPANY,

- A CORPORATION OENEW YORK.

LIGHTING-FIXTURE.

Specification of Letters Patent. Patented June 19, 1917.

Application filed May 5, 1913. Serial No. 765,444.

electric lights, and more particularly to the electrical connectionsbetweenthe body or junction part employed in such fixtures and the arms.I have hereinafter described my invention as specially adapted andapplied in connection with the chandelier shown and described in UnitedStates Letters Patent- No. 1,045,273 granted November26, 1912 to WilburH. Fisher, this'being an application in which the reliability ofelectrical connection which my invention afiords has proved of greatpractical value. While, however, my invention extends to the specificfeatures and details of the embodiment herein shown and described, whichare important on account of their specific advantages, yet the inventionis not confined thereto, but can be otherwise carried out and a plied}as will be evident both from the foil owing description and from myclaims. Various advantages that can be securedin connection with myinvention will hereinafter become apparent.

In the construction set forth in the Fisher patent, one of theelectrical contacts whereby connection is made between an arm circuitand a body circuit is resilient, and when an arm is inserted in the bodythis springy contact is first deflected and bent sidew'ise by comingagainstthe other contact and then springs back so that the'oth'ercontact rests in a sharp angle in the spring and is in a mannerinterlocked with it without necessarily havingxafiiy engagement exceptat this one place. ile the electrical connection thus secured would beentirely satisfactory both theoretically and practically if the armfitted in the socket without any play, it will upon consideration beseen that the form of contact shown in the Fisher patent does not allowfull advantage to-be taken of the reody contacts when there-is for anyreason on?- siderable up and down play of the arm in the socket.This'defect is due te thefiact' showin that the springy contact mustneeds be resiliently deflected to a greater extent during theinsertion'of the arm in'- the socket than after the arm has been pushedhome to its final position. In accordance with my invention, theinteraction of the arm and body contacts can be made such that theutmost play of an arm that is ever likely to occur under any conditionsmay'takeplace without interruption or impairment of the electricalconnection, and full advantage can be taken of the resilience of springyor resilient'contacts in maintaining the connection. These results canbe secured by making the parts so that when the arm is inserted in thesocket the resilient contact will be bent or sprung to one side withoutspringing back to any considerable extent, or so that the resilientcontact will be engaged at more than one place and forced against one ofthe surfaces so engaging it b'y the other.

In the accompanying drawings, Figure 1 is a perspective view of the endof a chandelier arm adapted for the fixture shown in the Fisher patentabove mentioned and having contact members constructed in accordancewith my invention.

Fig. 2 is a side elevation of the end' portion of'such an arm showingsomewhat more clearly than Fig. 1 the exact form of the contacts whenthe arm is not in the body;

Fig. 3 is a fragmentary .vertical section an arm with contacts likethose shown in Fi s. 1 and 2 in place in one of the arm-holes o the bodyshown in the Fisher patent above mentioned, this figure showing therelation of the arm contacts to the parts bf the body and the form whichthey assume when the arm is in place in the body.

In the particular device herein illustrated and described, the armcontacts a are the resilient ones, as in the Fisher patent, and theengagement and securing of the arm A in the body B and its constructionand internal features are the same as in the Fisher patent,.and the bodcontact means i and the construction of the body B are also exactly asshown in the Fisher patent, the body B having an external shell S and acentral portion I of insulating material in which are sockets i for thearms which afi'ord bearing for projections a, a on the arms so as toprevent them from turning, and this inner body I also having chamberssions of the sockets in which the body contacts i are exposed and engagewith the arm contacts a,-yet, although when an arm is in z with slightconvergencefor distance some-.

- what greater than the distance of the body place the body contacts 6lie between the arm contacts a, as in the Fisher patent, the

arm contacts a and their interaction'with the body contacts 73 and theassociated parts are nevertheless quite shown in the Fisher patent, boththe modes of action .above described being present.

As shown in the drawings, when the arm A is not in the body B itscontact members a project from the end of the arm in approxi- I mateparallelism-or, to be more accurate,

for a short distance with very slight divergence and for a greateradditional distance contacts i from the end of the arm when the arm hasbeen pushed home in the socket,

the distance apart of the approximately parallel portions a being asshown everywhere I less than the distance apart of the outer surfaces ofthe contacts i and are then bent or flared outward at a". The divergingportions a of the contacts beyond the bends a;

s of such length that'the distance between eir outer free ends a issubstantially less than the internal diameter of the barrel sockets 11,and the ends a are preferably rounded (as shown, by curling them quitesharply inward) so that when an arm is inserted in. the body orwithdrawnthey will slide easily against surfaces with which they come in contact,i

When, therefore, the arm A is inserted in the Socket 5 and pushed home,the body contacts i encounter the diverging ortions at;

of the arm contacts a and force t em apart and also bend the portions.a, apart and eventually come between them. In the early part of thismovement of the arm contacts an inward over the body contacts i the onlyportions of them that suffer. deformation.

are those between the end of the arm and the points ofengagement withthe body con- .tacts, the deformation being merely a resilient bendingapart of these portions. which tendsto make them concave outward. Withthe relative proportions and arrangement of the part shown, however, thefree ends a of the contacts a will come against the upper' a suchaswould make these portions concave inward. In the final posltion of'thediflerent from .what is arm in the body, therefore, each spring con tacta projectsfrom the inner'end of thearm A past the; body contact means iand is resiliently flexed between its points of-lateral engagement atits free end a and at the intermediate point in its lengthwhere it liesagainst the body contact 6'', this flexure being the reverse of itsflexure adjacent its fixed end that results merely from the presence ofthe contact i and serving to augment its resilient pressure against thiscontact i This double lateral flexure will permit a very considerable upand down play or tilt- 'ing of the arm in its socket with nothing morethan 'a decrease in the deformation of one ar'm contact a and itsresilient pressure upon the corresponding body contact i and theopposite efl'ect upon the other, without the slightestpossibility thateither arm contact a should even. for aninstant be out of engagementwith its body contact 2' While any suitable material may be employed,for the sake of combining the utmost resilience with good electricalconductivity it is preferable to make the arm contacts a of cold rolledsheet copper.

- -What I claim as new and desireto secure 1. In an electric connectionthe combination of a socket and a removable arm adapt- V by LettersPatent of the United States-is from and engaging said stationary contactat an intermediate point in said resilient contact and having its freeend engagin the wall of said socket whereby the 'res' ient contact isflexed by said wall and thereby pressed firmly agamst said stationarycontact u'nder any tilting movement of said arm.

2. In an electric connection the combination of a socket [and aremovable armhavmg a portion adapted to enter said socket',@said socket.-having a stationary'contact therem andsaid arm having extendingtherefrom a resilient contact ada ted to be engaged at an intermediatepoint y said stationary contact and thereby flexed in one direction andadapted to be engaged at its free end by the wall of'the socket andthereby flexed 1n the opposite direction;

3. The combinati n with a lighting fixture body or junction part havinga socket w th electrical contact means exposed therem, of a removablearm in said socket having a pair of spring contacts projecting from itsend at opposite sides of said body contact means .into engagementtherewith and resiliently bent apart thereby, the portlons of saldspring contacts beyond said body contact means extending into engagementwlth the walls of the socket and being thereby resiliently flexedtowardone another.

4. The combination with a lighting fixture 13o 95 ed to enter saidsocket, said socket having therein a stationary contact .an'd 'said armhaving a resilient contact extending therebody or jnnction part, havinga socket with electrical contact means exposed therein, of

a removable arm in said socket having a spring contact projecting fromits end and 5 engaging said contact means and thereby bent in onedirection, the portion of said Rspring contact extending beyond saidcontact means extending into engagement with the wall of the socket andbeing thereby resiliently flexed .in a direction opposite to that 10caused by engagement with the contact means.

In witness gvhereof, I have hereunto set myhand this 26th day .of April,1913.

. WILFRID LUMLEY.

Witnesses:' EDWARD R. CRAWFORD, ARTHUR B. Wilson.

